Right hand rule #1 and #2

One of the many "rules" we learn in physics is called the Right hand rule. No i am not joking you, it is called the right hand rule. However, you should not take this rule very lightly, as it does help you a lot with being able to identify the direction of the magnetic field (B).

Right hand rule #1

This rule is helps identify the direction of the current and the direction of the magnetic field. First of all to understand this rule, you must first know that all

rules regarding the right hand are used for conventional currents, whereas, the same rule for left hands deal with electron flow.

The first rule states that the direction the current is going through wire, the thumb is the indicator. The rest of the fingers are the indicator of the direction the magnetic field direction

Right Hand Rule # 2

This helps to identify the direction of of the current, and ultimately which side is North and which side is south of a coil/electromagnet. Coils are one of the ways to magnetically charge a conductor.

In this rule, the fingers represent how the electromagnet is coiled and the thumb is the direction of the conventional current

Test Review (Top 10 needs to know for this unit)

Series Circuits

A series circuit is the most basic type of circuit there is. A series circuits connects loads one after another in a single path.

Parallel Circuits

The next type of circuit is where one load is connected side by side, where there is more than a single path for the current to travel through.

Current (the flow of charge)

The rate of charge flow measured in Ampres (Coulombs/seconds). It is summarized using the Formula I (A) = Q(C)/t (s). To measure current, an ammeter is used and it measures the amount of coulomb that passes through a given distance over a period of time. An ammeter must be connected through a simple circuit. (1 electron = 1.602 x 10^-19 C)(1Coulomb = 6.2x10^18 Electrons)

The amount of current flow in a circuit (the amount of energy transferred to a device) depends on two factors:

1) The potential difference of the power supply (the amount of push)

2) the nature of the pathway through the loads that are using the electric potential energy

Direct Current

In a direct current or DC, the current flows in one direction from the power supply through the conductor to a load.

Alternating Current

In an AC, the electrons periodically reverse the direction of their flow. This reversal is carried out with he help of electric and magnetic forces.

Conventional current vs Electron flow

Electron flow is now the "well understood" theory where the current flow is a negatively charged electron repelling one another. From a negative terminal (-) to a positive terminal (+).

However in Conventional current the current flow was thought to move from the positive terminal to the negative terminal of any power supply.

Electrical Potential Difference (Voltage)

Electrical Potential Difference (Voltage) describes the amount of energy each coulomb of charge in a circuit releases to the load. Voltage is measured in Volts (V or J/C) and uses a voltmeter to measure the potential difference between two points, HOWEVER a voltmeter must be connected in parallel with a load. The formula for Voltage is V(V) = W (J) / Q(C) Sometimes W(work) is replaced with E (energy) in base formulas.

Voltage and Current

Because V=E/Q and I=Q/t

therefore E= VQ and Q= It

Hence E=VIt

Resistance (Ohm's Law)

Electrical Resistance is just as its name suggest, it is the amount of opposition to a flow of a current.

In Ohm's Law, it suggest that R = V/I because the Voltage to Current ration was constant for a particular resistor.

The resistance of a conductor often depends on its length (if length is doubled, resistance is doubled), cross-sectional area(if the area is doubled, the resistance goes to half of its original value), the material it is made of and its temperature.

Conservation of Electric charge

Kirchhoff's Current Law: the total amount of current into a junction point of a circuit equals the total current that flows out of that same junction

Kirchhoff's Voltage Law: the total of all electrical potential decrease in any complete circuit loop is equal to any potential increases in that circuit loop

Series

It=I1=I2=I3..=In

Vt=V1+V2+V3+...Vn

Rt=R1+R2+R3+...Rn

Parallel

It = I1+I2+I3+I4+...In

Vt=V1=V2=V3=Vn

1/Rt= 1/R1+1/R2+1/R3+.....1/Rn

Power

Power is the rate at which work is done.

For each particular load, a coulomb of charge is the energy carrier and the electric potential is the amount of energy that the charge is carrying. Therefore the amount of power dissipated in the load depends on how fast the charge arrives at the load.

Power has several formulae (power uses the units Watts or J/s)

P(W)=E(J)/t(S)

Since E=VIt

P=VIt/T

P= VI

Or

Because R=V/I

V= IR

P=I^2R

Therefore

P=IV

P=V^2/R

P= I^2R

Ohms Vs. Kirchhoff

Ohms Law.

Today we learned that Current is directly proportionate to Potential Difference (Voltage),

while Current is inversely Proportionate to Resistance

^current ^ Voltage

^current , the lower resistance is.

Kirchhoff's Current Law states that the total amount of current into a junction point of a circuit equals the total current that flows out of that same junction.

Kirchhoff's Voltage Law states that all electrical potential decreases in any complete circuit loop is equal to any potential increases in that circuit loop

Theses two laws are, in essence, summarizing the conservation of electric charge and conservation of energy, where there is no net gain or loss of electric charge/energy

Rip Ride Rock it? (no pun intended)

The thrill, the adrenaline, the excitement! Which 16 year old would not enjoy a day in an amusement park? On a warm summer day, walking into the theme park, the sun is in your eyes and the wind is blowing through your hair. The laughter of children is everywhere as you walk across the park in your flip flops to each you favourite roller coaster. As I walked through universal studios this summer, the rides there were mind-bogglingly thrilling. However amongst the Hulk, the Harry Potter rides, the Doom free fall tower, and the Rip Ride Rockit, I would have to say that the Rip Ride Rockit was by far the most electrifyingly fun.

The name of the ride is actually very clever. The reason why this roller coaster, in my opinion, has the best design, is because of its ability to capture the riders attention immediately. Music is often used to dictate the mood and theme of any piece or even.... RIDE. The most amazing thing about Rip Ride Rockit, is the fact that you can ROCK in it while you ride the "Rocket". Clever ain't it? As a rider, you are allowed to choose a song you like as you go through the ride. This ride was flawless in every design. They choose songs that would match the feel of the ride as well they designed it so that the coaster fit with the music. Such an impressive job, no wonder this is my favourite design for a roller coaster.

Right off the bat, if you look at the picture above, you can see a rise of 90 degrees. That rise, along with the music, sets the tone and the anticipation for a thrilling drop.

If i had a chance to go on any ride, i would love to go on this one again.

How does a Battery work in a circuit?

Ever since I was a young child, I have always wondered how such tiny, compact batteries are able to power up the biggest devices. How is it that the battery can transform the energy in a circuit to power up a load?

In a battery, there is a positive and a negative terminal. From the negative terminal, electrons produced and are trying to reach the positive terminal. In a circuit, there must be a conductor that connects the negative terminal (the battery) to the load, and from the load to the positive terminal. The electrons are pushed along the conductor and into the load, which then powers it. The amount of electrons that flow through a load, the same amount of electrons exit the load.

The reason batteries are still have power after a long time, is because, unless electrons are flowing from the negative to the positive terminal, the chemical reaction does not take place.

Energy Ball Experience.

Considering how Friday February 4, 2011 was the first full day of class, I was really unenthusiastic as I was headed towards class. I remembered how long the first semester felt and realized that I was only finished about half of the school year. But, this negative notion changed as soon as I walked into the first of physics class.

In groups of 5, we were expected to explain a strange occurrence; "why did energy ball began to flash and hum as fingers were placed on the metal contacts located on the side of the ball?". I was immediately intrigued.

1. Can you make the energy ball work? What do you think makes the ball flash and hum?

Placing two fingers on the metal contacts from the energy ball, a red light began to glow and an eerie buzzing noise started to sound. As our group looked more in depth and took a closer look at the strange phenomenon, we realized that a closed circuit is what makes the ball flash and hum. A battery must have already been provided within the ball and the only thing left to do was to connect the metal contacts in order for the electricity to flow.

2. Why do you have to touch both metal contacts to make the ball work?

By placing two fingers on both metal contacts, a closed circuit is created. The closed circuit allows the electricity to flow continuously, resulting in the flashing lights and the eerie hum.

3. Will the ball light up if you connect the contacts with any material?

Because our group has already established that the ball will only light up through a closed circuit, we already knew that the materials which connected the contacts must be able to conduct electricity. Often, water, metallic objects and so forth are great electricity conductors, on the other hand, materials such as fabric and paper (insulators) do not conduct electricity, hence the ball did not work when those materials were touching the metal contacts.

4. Which materials will make the energy ball work? Test your hypothesis.

My hypothesis was correct, based on observations, only conductors (i.e metal) made the energy ball work and not insulators.

5. This ball does not work on certain individuals- what could cause this to happen?

The reason why the ball would not work on certain individuals is due to dry hands. I based my reasoning on the fact that the ball would not work if I merely used my nails to touch the metal contacts. I would hypothesize that the ball would not work on certain calloused or dry hands act because they act like insulators, similar to nails.

6. Can you make the energy ball work with all 5-6 individuals in your group? Will it work with the entire class?

Yes, the energy most certainly did work with all the individuals in my group as well as the whole class. As long as everyone was connected through something as small as a pinky, the circuit functioned

7. What kind of a circuit can you form with one energy ball?

A series circuit can be formed using one ball.

8. Given two balls (combine two groups), can you create a circuit where both balls light up?

As two groups, it was most certainly possible to make both balls light up in a circuit. Our 2 groups merged and formed a large series circuit. So we got into a circle and on one end of the circle we placed the energy ball between two people who had contact with the metal contacts and on the opposite side of the energy ball pair, we placed the other energy ball and did likewise.

9. What do you think will happen if one person lets go of the other person's hand and why?

The ball would stop working because, in a circuit, there has to be a continuous flow of electrons.

10. Does it matter who lets go? Try it.

No, it does not matter who lets go. As long as the series circuit is considered "open", there would be an insufficient flow of electron. However, if it was a parallel circuit then the person who lets go is very important. The wiring in a parallel circuit is much more complex and depending on who lets go, it could potentially result in a circuit that turns one ball on or both balls on.

11. Can you create a circuit where only one ball lights (both balls must be included in the circuit).

It is very much possible to create a circuit with both balls and only lighting one of them up. We would make a circle and then make line right across the centre of the circle (across the centre; the diameter). With this extra line in the centre, we have basically made 2 circles. So, if we were to disconnect one of the people joining their hands on one side of the circle then the other ball would still be on. However if someone were to disconnect contact at the same area at which the diameter connects with the circle, both balls would still be on, but with if someone else disconnects, it would result in both balls being off. In essence, we would make a parallel circuit

In this picture below, imagine that the batter was in the centre and that the light bulbs were on either side of the circuit.

At any given location, one of the bulbs would still be on if you open up one of the sides so that there is no longer a circuit. The only location that would turn of both bulbs is if you open up the area at which the battery joins the larger conductor rectangle.

12. What is the minimum number of people required to complete this?

The minimum number of people needed to complete the parallel circuit is four.